Stringing block



July 23, 1963 A. MOAULEY 8 STRINGING BLOCK Filed Aug. 27, 1959 2 Sheets-Sheet 1 2 Sheets-Sheet 2 Filed Aug. 27, 1959 3,098,638 STRINGING BLOCK Anthony McAuley, Maywood, Ill., assignor to A. B. Chance (Iornpany, Centralia, Mo., a corporation of Missouri Filed Aug. 27, N59, Ser. No. 836,448 3 Claims. (Cl. 254134.3)

This invention relates to a stringing block and a method of stringing flexible members, particularly designed for stringing multiple conductors and a messenger or support cable from poles, as in a power distribution system.

Many electrical distribution systems have three or four conductors strung from a cable \OI' messenger wire supported between poles. In installing a system of this type, or recabling an old installation, the conductor and messenger wires must be strung along the poles from which they will be supported, placed under tension and the installation completed as by cabling the conductors and messengers together and securing the resulting cable to each pole. At the present time a multiple sheave arrangement is commonly used in stringing such cables.

The stringing sheaves are provided with plate-like spacer 7 elements between the individual sheave wheels which are intended to keep the conductors from tangling. In practice, however, the cables sometimes jump over the spacers, become tangled or jammed between the spacers and sheaves and are sometimes cut or otherwise damaged. A substantial portion of the time involved in stringing cables is spent in freeing jammed conductors and in keeping the conductors straighlt.

A principal object of the present invention is the provision of a new and improved stringing block and cable stringing method which greatly facilitates the operation, reducing the time required and eliminating damage to the conductors.

One feature of the invention is the provision of a stringing block including a frame having a plurality of vertical and horizontal rollers carried therein, the vertical and horizontal rollers defining a plurality of separate wire guide sections. Another feature is that the frame includes a removable portion which opens each of the wire guides permitting removal of the stringing block from the cables after they have been strung and placed under tension.

A further feature is the provision of such a frame with a separable messenger-receiving guide portion as a removable handle on the frame of a pole-mounted stringing block or a removable supporting sheave for a midspan stringing block.

Yet another feature is the method of stringing a plurality of conductors and a messenger wire comprising securing a stringing block to each of the poles, pulling a messenger cable through the stringing blocks and placing it under tension, pulling conductors through the stringing block and placing them under tension and finally removing the stringing blocks from the tensioned cable and conductors.

Further features and advantages of the invention will readily be apparent from the following specification and from the drawings in which:

FIGURE 1 is a view illustrating use of the invention;

FIGURE 2 is an elevation of a pole-mounted stringing block embodying the invention;

FIGURE 3 is a section taken generally along line 33 of FIGURE 2;

FIGURE 4 is an enlarged plan view of the stringing block of FIGURE 2 with a portion of the frame broken away for clarity;

FIGURE 5 is an elevation of a mid-span stringing block with portions in section;

3,098,638 Patented July 23, 1963 FIGURE 5A is a fragmentary detail of the removable sheave shown in FIG. 5; and

FIGURE 6 is an enlarged fragmentary detail of the cover securing and roller mounting structures.

In FIGURE 1 a pair of poles 10 and 11 are illustrated each having a stringing block 12 mounted thereon. A messenger or supporting cable 13 is strung between the blocks 12 and supports mid-span stringing blocks 14. Hand lines 15 connected with each of the mid-span stringing blocks '14 facilitate positioning of them at appropri ately spaced distances between poles 10 and 11. A conductor 16, of which there may be two or more depending upon the nature of the particular installation is threaded through and carried by the pole mounted and mid-span blocks 12 and 14. Briefly, the stringing blocks are used in the following manner. Pole mounted blocks 12 are secured to the poles along which the conductors are to be strung and messenger cable 13 is threaded through them. Before the messenger is taken up, mid-span blocks d4 are attached to it and a hand line may be threaded through the pole mounted and mid-span blocks for each of the conductors. The messenger is placed under tension raising the mid-span blocks into the air and the conductors are pulled into place. The conductors them selves may then be placed under tension and the stringing blocks removed. This brief discussion of the method of stringing conductors will be amplified following a detailed description of the illustrated embodiment of the stringing blocks.

Turning now to FIGURES 2-4, it will be seen that the pole-mounted stringing block 12 includes a rectangular frame made up of a base 17, upstanding end members 18 and 19 and a cover 20 which is hinged at 20a with the top of end member 18. End member 18 is suitably secured to mounting plate 23 as by bolts 24 and the mounting plate is provided with a chain 25 by means of which it is secured to pole 10. Mounting plate 23 extends below the bottom of frame base member 17 and a brace 26 provides additional support for the assembly. The area defined by the rectangular frame is divided into a plurality of separate wire guide sections by horizontal and vertical rollers 27 and 28, respectively. The horizontal roller includes an axle 30 extending between frame end members 13 and 19, spaced above base member 17, and having a plurality of independent sleeve rollers 31 mounted thereon and free to rotate. Vertical rollers 28 include an axle 32 threaded to base plate 17 and having a sleeve 33 rotatable thereon. The upper end of each of axles 32 is preferably pointed for reception in a complementary tapered recess '34 in cover member 20. Vertical rollers 28 are located in alignment with joints 31a between horizontal roller elements 31 and together with the horizontal rollers define a plurality of cable receiving sections which are closed on top by a removable cover member 20. A handle 35 is removably secured to the upper surface of cover 20, as by a pair of wing nuts 36, and together with the cover defines a guide for messenger cable 13.

Cover 20 is provided with a hasp 37 which engages an eye 38 on end member 19 and may be secured in place by a snap or the like 39.

It will be noted that a pair of vertical rollers 28 are provided adjacent the frame end members 18 and 19. This prevents the conductors from rubbing against end members 18 and .19 or against base plate 23 or pole 10 as they are pulled through the stringing block.

Mid-span stringing block 14, FIGURE 5, is basically the same as pole-mounted stringing block 12 and the description of the frame and rollers will not be repeated. Bracket members 42 and 43 secured to the upper surface of cover 20 provide a mounting fior supporting sheave 44- by which the mid-span stringing block is movably carried on messenger cable 13. The brackets are preferably slotted as illustrated at 45 to permit removal of sheave 44, facilitating attachment of the stringing block to and removal from messenger 13. An eye 46 extending downwardly from frame base member 17 facilitates attachment of hand line for guiding and positioning the mid-span stringing block.

As pointed out above, the first step in. stringing cables is to secure a series of pole-mounted blocks 12 to the poles along which the conductors are to be strung. As this is done a hand line is run through handles 35 of each of the pole mounted blocks =12 and, after they have been secured to the poles at the proper height, messenger 13 is pulled through. While the messenger is hanging loosely between the poles mid-span blocks 14 are attached thereto, the number used between each pair of poles depending upon the distance between them. At the same time, hand lines for each of the conductors are threaded through the guide sections defined by horizontal and vertioal rollers 31 and 3-2 of the mid-span and pole-mounted stringing blocks. Messenger 1 3 is preferably placed under tension and conductors 16 pulled into place. When all three conductors are in position their free ends are anchored and they are placed under tension. With these stringing blocks the cable reels for each of the conductors may be mounted on a single axle and all placed under tension at the same time, as by means of jacks acting on the axle. The conductors move freely through the cable stringing blocks by virtue of the horizontal and vertical rollers which divide the frame into cable guiding sections, and the cables may not jump from one section to another nor become jammed or damaged. After the cables are tensioned the mid-span stringing blocks may be moved to the closest pole where a member of the stringing crew rem'oves sheave 44 and opens cover 20 freeing the stringing block from the cables. At the same time handle 35 may be removed from pole-mounted stringing blocks 12, cover 20 opened and the stringing block taken from the pole. As the stringing blocks are removed the messenger and conductors may be cabled together by a suitable mechanism and secured to a cross arm (not shown) on each of the poles.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes therefore, in the construction and arrangement may be made Without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

1. A stringing block comprising a rectangular frame having a base two ends and a cover, said cover being hingedly attached to one of said ends; a releasable lock norm-ally maintaining said cover connected with the other end; a row of spaced, vertical axles, each having one end thereof rigid with said base and disposed substantially perpendicular thereto, said cover having a plurality of recesses therein for receiving the other end of corresponding axles; a horizontal axle rigidly interconnecting said ends, whereby to define a number of wire guide sections; a cylindrical sleeve roller in surrounding rotatable relationship with each axle respectively, whereby wires may be easily drawn through the wire guide sections when the cover is connected to said other end and the wires may be easily withdrawn from the string block when the cover is released from said other end; and means on the frame for supporting the same.

2. A stringing block as set forth in claim '1, said sup- .porting means including a bracket mounted on said cover; and a rotatable guide removably attached to said bracket for receiving a messenger cable, whereby the block may be guided into operating position along the cable.

3. The invention of claim 2, an eye mounted on the base therebelow; and a hand line attached to the eye for positioning the block along the cable.

References Cited in the file of this patent UNITED STATES PATENTS 224,027 Metzler Feb. 3, 1880 1,209,286 Goodwin Dec. 19, 1916 1,301,263 Hill Apr. 22, 1919 1,650,904 McKissick Nov. 29, 1927 1,749,515 Sleeman Mar. 4, 1930 1,831,306 Kakimoto Nov. 10, 1931 1,972,049 Thomas Aug. 28, 1934 2,493,687 Mott Jan. 3, 1950 2,527,651 Pieper Oct. 31, 1950 2,949,279 Eitel Aug. 16, 1960 2,983,037 Hendrix May 9, 196-1 FOREIGN PATENTS 357,265 France Dec. 22, 1905 58,672 Austr-ia Apr. 10, 1913 562,261 Great Britain June 23, 1944 1,032,808 Ger-many.-- "June 26, 1958 1,059,523 Germany June 18, 1959 

1. A STRINGING BLOCK COMPRISING A RECTANGULAR FRAME HAVING A BASE TWO ENDS AND A COVER, SAID COVER BEING HINGEDLY ATTACHED TO ONE OF SAID ENDS; A RELEASABLE LOCK NORMALLY MAINTAINING SAID COVER CONNECTED WITH THE OTHER END; A ROW OF SPACED, VERTICAL AXLES, EACH HAVING ONE END THEREOF RIGID WITH SAID BASE AND DISPOSED SUBSTANTIALLY PERPENDICULAR THERETO, SAID COVER HAVING A PLURALITY OF RECESSES THEREIN FOR RECEIVING THE OTHER END OF CORRESPOND ING AXLES; A HORIZONTAL AXLE RIGIDLY INTERCONNECTING SAID ENDS, WHEREBY TO DEFINE A NUMBER OF WIRE GUIDE SECTIONS; A CYLINDRICAL SLEEVE ROLLER IN SURROUNDING ROTATABLE RELATIONSHIP WITH EACH AXLE RESPECTIVELY, WHEREBY WIRES MAY BE EASILY DRAWN THROUGH THE WIRE GUIDE SECTIONS WHEN THE COVER IS CONNECTED TO SAID OTHER END AND THE WIRES MAY BE EASILY WITHDRAWN FROM THE STRING BLOCK WHEN THE COVER 